Polyolefins are a class of polymers derived from simple olefins. Known methods of making polyolefins involve the use of Ziegler-Natta polymerization catalysts. These catalysts polymerize vinyl monomers using a transition metal compound to provide a stereoregulated polymer.
Numerous Ziegler-Natta polymerization catalysts exist. The catalysts have different characteristics and/or lead to the production of polyolefins having diverse properties. Moreover, polyolefins made with the use of Ziegler-Natta polymerization catalysts vary in stereoregularity, molecular weight distribution, impact strength, melt-flowability, rigidity, heat sealability, isotacticity, and the like.
Silica supported Ziegler-Natta polymerization catalysts generally are made through a precipitation method using an organic magnesium compound starting material. The organic magnesium compound is chlorinated to provide magnesium chloride. However, the chlorination procedure tends to badly corrode manufacturing equipment and introduces harmful environmental concerns.